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Srt Intake Problem - Ecu Fried?


altezza02

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Hi everyone, I'm new to this forum, rolling in a 2002 IS300 :D It's probably a bad start for me to get straight to asking for help without contributing much, but this is very urgent.

I recently purchased a used SRT intake system with piggyback unit from eBay. The installation itself was not hard at all, though time consuming as far as the soldering goes. When I started the car, that's when problems started appearing.

After letting it idle for half an hour, I tried the car. The rev won't go higher than 2000rpm. At first, I thought it was the MAF sensor !Removed! up, but without the MAF the car should not go higher than 3000rpm, not 2000rpm. It can't be the intake itself either because if it is, my car would be dead by now. CEL didn't come on either. Finally, I concluded that there is something wrong with the piggyback unit. I checked all the connections, and they looked fine. I followed the instructions exactly - tapped into the wires required, with the exception of one wire where it has to be routed through the unit. So I tested it - I drove it around for a while, finally CEL came on. To confirm that it's the piggyback unit's problem, I reconnected the original wires and took out the piggyback unit.

My car won't idle now. :chairshot:

After taking out the piggyback unit, when the car starts, it would just die down with no idle rev. Convinced that there is definitely something wrong with the ECU now, I disconnected the battery, waited a night, and reconnected this morning to see if it would heal itself...

...nope. In fact, it barely starts. :chairshot: :chairshot:

Feeling extremely *BLEEP*ed and very convinced that the guy that sold me his used SRT intake probably had a bad piggyback unit, (it didn't even have the original SRT label) I did the last thing I could - disconnected the MAF sensor so it can go to the defaults. I slammed on the gas immediately after trying to start the car. It coughed, and coughed, and coughed. Finally, it starts!

Oh wait, my traction control died. :chairshot: :chairshot: :chairshot:

I'm completely lost - the traction control died, my car coughs at start, it had to be forced into default failsafe mode, and when I took it to a friend's auto shop to test the engine codes, it spewed huge errors - disconnected circuits, parts not responding, what-have-you.

We basically concluded that the ECU died. Still trying to figure out why, we cracked open the piggyback unit.

Here is where I'm doubtful of his words - he said the piggyback unit looked like it was for an automatic transmission IS300. I started thinking, "Really? There's two different piggyback units?" But regardless, it seems my ECU is...gone. :wacko:

So I guess what I'm trying to ask are:

1) Is there really two different piggyback units?

2) Does it really sound like the ECU is dead? How much does another ECU would cost me?

Any help would be appreciated, thanks!

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Sounds like it went into "limp" mode on the first try, trying to protect the motor. After that, you're probably correct that the ECU is fried or some connections were broken when you disconnnect the solders wires.

The TRAC light usually comes on when the engine goes into limp mode.

I looked at a couple sites that sell SRT and didn't see any place to specify auto or std transmissions on the order forms. I kinda think all the piggy backs are alike.

Do a Google search on "used Lexus parts". I've found ECU's listed before on some of the salvage sites. Sorry, but I don't have the bookmarks anymore.

Maybe try this guy for a replacement ECU. http://www.billystoyotaparts.com/

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Sounds like it went into "limp" mode on the first try, trying to protect the motor.  After that, you're probably correct that the ECU is fried or some connections were broken when you disconnnect the solders wires.

The TRAC light usually comes on when the engine goes into limp mode.

I looked at a couple sites that sell SRT and didn't see any place to specify auto or std transmissions on the order forms.  I kinda think all the piggy backs are alike.

Do a Google search on "used Lexus parts".  I've found ECU's listed before on some of the salvage sites. Sorry, but I don't have the bookmarks anymore.

Maybe try this guy for a replacement ECU.  http://www.billystoyotaparts.com/

Thanks for the info - I never knew there was such thing as limp mode.

What happened was the TRAC light blinks rather than staying on. Nothing can stop it from blinking. Traction control was confirmed off when I as able to peel off the road. (though I can't go over 3000rpm now)

I've already looked in some salvage sites, and I did find a few - but I would like to confirm something - is there different ECUs for auto and manual? The only think I know relevant to that is the 2001 model used a different ECU.

But why would it suddenly try to "protect" the motor? Isn't the piggyback unit (assuming it actually works) supposed to fool the ECU rather than trying to mutilate it?

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Sounds like it went into "limp" mode on the first try, trying to protect the motor.  After that, you're probably correct that the ECU is fried or some connections were broken when you disconnnect the solders wires.

The TRAC light usually comes on when the engine goes into limp mode.

I looked at a couple sites that sell SRT and didn't see any place to specify auto or std transmissions on the order forms.  I kinda think all the piggy backs are alike.

Do a Google search on "used Lexus parts".  I've found ECU's listed before on some of the salvage sites. Sorry, but I don't have the bookmarks anymore.

Maybe try this guy for a replacement ECU.  http://www.billystoyotaparts.com/

Thanks for the info - I never knew there was such thing as limp mode.

What happened was the TRAC light blinks rather than staying on. Nothing can stop it from blinking. Traction control was confirmed off when I as able to peel off the road. (though I can't go over 3000rpm now)

I've already looked in some salvage sites, and I did find a few - but I would like to confirm something - is there different ECUs for auto and manual? The only think I know relevant to that is the 2001 model used a different ECU.

But why would it suddenly try to "protect" the motor? Isn't the piggyback unit (assuming it actually works) supposed to fool the ECU rather than trying to mutilate it?

Yes the trac light would be blinking, and possibly another light. I can't think of which one right now. The piggyback may be defective or something got messed up during installation or removal. The engine goes into limp mode because is senses that something is wrong that could cause engine damage. Therefore it restricts the RPM to allow some driving, but limits the RPM.

My 2001 - 2002 parts list just gives different part numbers for 01 and 02 ECU, but no separate number for manual and auto. When your RPM was limited, something with the SRT thingie or the hookup told the ECU that there was an error somewhere. Had the piggyback been ok and the install ok, then that would not have happened.

You really need to get those codes and then find out what they are and what the fix is. In the meantime I'd take a VOM and check continuity on all the wires and connections that were involved in the installation and removal of the piggyback. One open circuit could be causing all the problems. Of course you also need to check all the fuses and relays in the system, as one or more of those could have gotten shorted.

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Well before I reconnected the battery for the first time, I already re-checked all the connections and the diagrams twice, so that is out of the option. The only thing I can think of is the piggyback. (I kinda find it difficult to believe a piggyback from SRT would have no labels and a big "300" written with permanent marker on it)

I already removed the piggyback and reconnected the original wires. At this point, I'd be very lucky to have it running without replacing the ECU.

*sigh* :cries:

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Sorry I couldn't help more.  I have heard of it happening a couple times, but usually the soldering wasn't right.  Good luck.

No, no...I appreciate the help. I'm just kinda disappointed I couldn't give a more proper introduction here. Maybe I'll go ahead and do that once I get my car fixed...talk about bad impressions...this is only my third mod too (first being a drop, then 5zigens)...:geek:

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Sorry I couldn't help more.  I have heard of it happening a couple times, but usually the soldering wasn't right.  Good luck.

No, no...I appreciate the help. I'm just kinda disappointed I couldn't give a more proper introduction here. Maybe I'll go ahead and do that once I get my car fixed...talk about bad impressions...this is only my third mod too (first being a drop, then 5zigens)...:geek:

I know quite a few guys who love the SRT intake. I never got one for the very reason that you have to solder wires into the ECU. That was kinda scary for me.

Anyway, good luck.

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